An updated look into reactive oxygen species and cyclophosphamide-induced ovarian damage

It is estimated that 70-75% of cancer survivors are interested in parenthood with an astounding 80% struggling with reduced fertility. Cancer treatments can deteriorate the ovarian primordial follicular pool and reduce the quality of fertilizable eggs through cytotoxicity and induction of premature ovarian insufficiency (POI). Cyclophosphamide is one of the most commonly used chemotherapeutic agents and is also utilized as an immunosuppressant in autoimmune diseases and in bone marrow transplants. Accordingly, those treated with cyclophosphamide face increased risks of POI and infertility, potentially arising from the toxic effects of its metabolites acrolein and phosphoramide mustard. The downstream accumulation of oxidative stress mediated by reactive oxygen species (ROS) from mitochondrial damage, activation of apoptotic pathways, and the disruption of enzymatic and non-enzymatic machinery may facilitate premature follicle activation, follicular apoptosis, and oocyte quality deterioration resulting in the loss of the ovarian reserve and POI. Furthermore, direct disruption of key antioxidants, such as superoxide dismutase (SOD) and glutathione (GSH), by acrolein and myeloperoxidase (MPO) may play a key role in ovarian disruption and the worsening oxidative state in those seeking treatment with cyclophosphamide.